Coolant preferences

[Noct]

I've had just water in one of my cars for about 10 days after replacing the water pump... was going to go for the Peak 50/50 that's on sale and re-fill the car. Thought I should post and see if that type is objectionable for some reason. Thanks.

[BMWtyro]

Noct,

It must be a phosphate-free coolant so as not to corrode the aluminum radiator and the many aluminum engine components.

I use BMW Genuine coolant in all of mine; it seems to be worth it.

Jeff

[GripGreg]

I've read a lot that it's best to fill with top notch anti-freeze (not 50-50),
and the rest, about 1/3, with 'distilled water' because it doesn't rust.
I would also add some 'Water Wetter'!
I hope all of your hoses are new!
Greg
Ps,,I also hope you know about the bleeder valve on top of the thermostat housing? VERY IMPORTANT!!
PPs,,Also, only add whatever, when the thermostat is open, which means after a decent warm-up,,,watch the Temp. needle.

[BMWtyro]

Amen, Greg! I should have mentioned those points, as that is how I do it as well.

And Noct: don't forget to pull that plug located 'waaay back on the right side of the engine near #6 cylinder; it releases about another gallon of old coolant and sludge (or in your case water and sludge) . . . or so it seems. Always do that both before and after flushing --- I couldn't believe how much crud came out of mine both times!

Jeff

[JAWS]

The plug you are referring to way at the back by cylinder #6 , where is the plug exactly? I want to do mine , as I have never done this , and I am getting ready to do my water pump and thermostat as well. I have completely drained mine from the block , but I think you are referring to a different plug where sludge can build up. Tell me a little more about the size and location of this plug so I can drain mine as well. Thanks so much in advance!

[JAWS]

What exactly should we know about the bleeder valve on top of the thermostat? Getting ready to do this same procedure on mine......thermostat and water pump. Also any opinions on what temp thermostat to purchase? I sell bavauto has 71 degree and 75 degree and 80 degree. I think 80 is standard but I was thinking about going cooler to 71 or 75. Opinions on this please. thanks!

[Ralph in Socal]

Read the attached. It's for a radiator but pretty much the same job. Pics of said block drain plug included twice. I've used Zerex G-05 as it is the same composition as BMW coolant - also not cheap.

viewtopic.php?t=8020


Ralph

[BMWtyro]

Jaws,

I found this link to an image on mye28.com. It is the silver plug located in the block just below #6 exhaust port in the image. IIRC, it has around a 17 - 19 mm hex.

http://i557.photobucket.com/albums/ss18 ... G_0676.jpg

Hope this helps.

Jeff

[BMWtyro]

Jaws,

I couldn't find a lower-than-stock-temp t-stat for mine; I think that is because it must use the early-style stat. If I am wrong about this, somebody please let me know.

As far as the bleeder screw goes: get the car up to operating temp, heater full-on, and raise the nose of the car so that the bleeder is higher than anything else on the engine (8 - 10 inches seems to work for me). With the engine running, slowly crack that bleeder enough to bleed any air which may be trapped there (remember: air bubbles go up). As soon as nothing but coolant (and very hot coolant, I might add) comes out of the bleeder's "window", you are done.

NOTE: Use extreme care because you will be working quite close to a rotating fan, belt and pulleys.

Jeff

[tschultz]

Amen, Greg! I should have mentioned those points, as that is how I do it as well.

And Noct: don't forget to pull that plug located 'waaay back on the right side of the engine near #6 cylinder; it releases about another gallon of old coolant and sludge (or in your case water and sludge) . . . or so it seems. Always do that both before and after flushing --- I couldn't believe how much crud came out of mine both times!

Jeff

Great information, I didn't know about this!! Sound like something worth doin' the next time I'm in there...

Also Ralph, thanks for the great link to that DIY article with photos!

[GripGreg]

Also, make sure you have the bleeder valve that uses I think, a 5 or 6mm wrench, NOT the old style screwdriver.
Take yours to any stealer to make sure of the size. It may not cost $5!
LB BMW tried to sell me the wrong one, till I showed them my old one.
The guy said, "This is what they use!" I knew otherwise. So beware of that!
Of course, I kept the cover that came with the car.
And, don't over tighten it!! It is small & doesn't need a lot!
Also, you living in the bay area, it doesn't get too hot, right?
Because of that, I would recommend the 80 degree thermostat.
I've heard the M30 doesn't run efficiently if it isn't warm enough.
Also, make sure it is installed with the correct side up!
Make a mental note when you remove the old one, or compare the two & use a marks-a-lot on one side or other.
I know you may think I'm joking here, but, I've read about problems because of that very thing.
I'll let you know when I'm joking around, okay?
Oh, yeah; when you bleed it, don't unscrew the valve all the way out,
just till it bleeds, hold it there & re-tighten & check the over flow tank.
Yep; all this while the car is idling!
Greg
Ps,,I would use some sort of anti-seize gunk as it'll be awhile before you get back there,,we hope!

[BMWtyro]

+1 to what Greg said.

And one more thing: if your car requires the early (longer) thermostat style as ours does, you must install the O-ring behind the thermostat and a gasket in front of the thermostat. Trying to get the clearances to "work" just about drove me nuts until I figured this out.

Jeff

[Da_Hose]

I just changed my car over to waterless coolant. That is the way to go.

Jose

[GripGreg]

Jeff, or anyone, can/will you find an exploded view of the thermostat & housing so I can get a clear view of what Jeff means?
Do the early housings look different compared to the later ones?
I've read this before, but,,,,?
Thanx in advance,,,,Greg

[jacko]

Jose, I agree once everything is sorted out.

[slofut]

I've had just water in one of my cars for about 10 days after replacing the water pump... was going to go for the Peak 50/50 that's on sale and re-fill the car. Thought I should post and see if that type is objectionable for some reason. Thanks.

Zerex G05 and distilled water!

[BMWtyro]

Greg,

This is the only stupid diagram used for any of the M30 Sixers, all the way from the first in 1977 to the last in 1989 --- and it is wrong for at least some of them (such as my 8/84-built car):
http://www.realoem.com/bmw/showparts.do ... g=11&fg=35

The O-ring must go behind the t-stat for proper clearance on such cars, and a gasket (not illustrated anywhere on RealOEM or Penske that I can find) must be used ahead of the t-stat to seal the stat housing halves. Here it is:
http://www.eeuroparts.com/Parts/41975/E ... 531250357/

Also, you must know whether your car uses the "old" or "new" t-stat design, which is somehow indicated by numbers on the t-stat housing (if I can find that "formula" again, I'll post it).


Jose,

What is "waterless coolant"? Is it available as non-phosphate? Sounds interesting.

Jeff

[Da_Hose]

Take look through this thread.

viewtopic.php?t=22765

Jose

[Noct]

Wow, glad I posted this thread... sure I'll be back with some questions before I do this. Thanks.

[Chris Wright]

This was posted in another link:

• "Hey Bimas,
  I was told that coolant that contain phosphates are bad for the aluminum head in the M30 engine. So I went to BMW dealer to get coolant and read on the label that it contained phosphates. What is your take on that?" thanks

I found this to be a bit of a surprise, as BMW always recommends a phosphate free coolant, but not for the reasons most people generally assume. The original "BMW Blue" coolant is BASF G48 and is defiantly phosphate free. I wonder If they have changed the brand of coolant for the North American market?

There is a common misconception that phosphates are bad for Aluminum engines, but the reverse is actually true. Phosphates were added to the old "Green" anti-freezes in the U.S. to specifically add protection for aluminum when aluminum started showing up in engines in the U.S. This misconception comes from the white film that the phosphates deposit on the inside of the engine. It is this film that provides the protection for the aluminum and is often confused with harmful mineral deposits that can form in cooling systems.

The downside is that phosphates in large enough concentrations are a water softener and can help minerals to drop out of solution, forming deposits. In the U.S., the water is generally soft enough and the phosphate concentrations low enough, that posable mineral deposits were considered minor**. In Europe, however, the water is generally very hard and that is why BMW recommends phosphate free coolant to ensure against mineral deposits.

But the whole thing is moot if you use de-mineralized (distilled) water, as there are no minerals to drop out of solution!

The bottom line is that if you always do a complete flush of the system and use distilled water, you can "get away" with using most any of the coolants, but start mixing coolants and/or using tap water and you can quickly get into trouble.

The worst are those "Any Make, Any Model, any Color" Anti-freezes like the Prestone, but there are others. It is basically a Dex-Cool coolant with phosphates added and alleges that it can be mixed with any other coolant. The Federal Trade Commission has issued a cease and desist order to stop this kind of false advertising and there is a class action law suit pending.

** Even so, distilled water was always recommend because there were local areas that can have very hard water.
__________________

Changing the Coolant:

The system holds 12.7 qts or about 3 gal. of coolant and at a 50/50 mix that would be about 1.5 gal. of anti-freeze to 1.5 gal. of distilled water. Buy 2 gals of anti-freeze and at least 3 or more gals of distilled water.

If you don't like paying $25 a gal. at the dealer for the "BMW Blue" (G48) antifreeze, you can use the $12 Zerex G05 coolant that Mercedes, Ford, Chrysler use. It is basically the same G48 "HOAT" chemistry with an additional additive to protect cylinder liners. You can find it a NAPA.

I'd stay away from the GM "Dexcool" and other "OAT" chemistries in the chain store offerings like Prestone ...... But, if you insist on trying to get away with using one of these, it may work IF you use distilled water (and never use anything else) and do a complete flush and refill and never mix any other coolants with it.

I would get one of those reverse flush kits and install the "tee" in the hose** between the back of the head and the heater valve. When you are done flushing with the garden hose, pour a gal. of distilled water (or 2 if you can't get the block plug out, they are only 98¢) through the system to displace as much of the tap water trapped in the block with the distilled water as possible. It is not necessary to get it all out, a little bit of tap water is desirable.

Now put back in all of the drain plugs***, open the Bleeder Valve on the T-Stat housing and pour in 1.5 gals (6 Qts.) of the BMW or Zerex G-05 anti-freeze to mix with whatever is already in the block and top off the system with whatever is needed from the gal. of pure distilled water (closing the Bleeder Screw when bubbles stop). Since the system is about 3 gals and you have 1.5 gal of anti-freeze in it, topping it off with the pure distilled should give about the proper 50/50 mix.

Now with the Bleeder Screw closed, turn the heater temp to full and warm the engine to normal operating temp. Reopen the Bleeder Screw with the engine idling until any bubbles stop coming out. It may take several tries to get fully bled. It helps to have the front raised, or take it out and drive it (don't let it over heat) or let it sit overnight.

Top up the remaining half gal. of coolant with distilled water and you have a gal. of 50/50 mix for the shelf for topping up the system.
________


** If you don't like the look of the "tee" in this hose, use scraps of hose to install it and then when you are done flushing, reinstall the OEM hose before filling the system.

*** Torque = Radiator drain plug - 18 to 27 In/lbs , Engine block drain plug - 32 to 40 ft/lbs

[Noct]

I've been a little nervous since having the water in the car. The guy who helped me out with the water pump said it takes quite a while for rust to develop, but of course it is a pretty old car and I've only owned it for the past 3 yrs.

Chris, I feel better since you said a little bit of tap in there is actually desirable. I'm confused too, however, because I think you emphasised a couple times never putting anything but distilled water.

Hopefully I can get to this soon. Sounds a little more involved than I expected. What do I need the garden hose for? I guess this might be a good time to buy a torque wrench instead of getting it from the tool library again.

[Noct]

I would also add some 'Water Wetter'!
I hope all of your hoses are new!

God knows how old the hoses are, but I really really do not feel like changing them. Also have no idea about water wetter.

[GripGreg]

Google 'Water Wetter'.

[jacko]

In a previous life, I spent a lot of time playing with Turbo Volvos. Most of us ran Water Wetter in them. I never felt that I saw much difference in overall cooling, but I did like it to help cool "hot spots" in the engine/head and with water cooled turbos and when short Le els of high boost would suddenly "spike" temperatures. It's inexpensive and certainly does no harm.

Jack

[BMWtyro]

Noct,

Remember that radiator coolant is also a lubricant for the water pump and any other moving parts in the system. You know how slimy it feels when you get some between your fingers; well, that's a good thing to have in a cooling system.

Jeff